Device for bounding fluid cushions of a ground effect machine



y 25, 1967 J. H. BERTIN ETAL 3,

DEVICE FOR BOUNDING FLUID CUSHIONS OF A GROUND EFFECT MACHINE Filed May 4, 1966 Fig. 1

i ,2! V/ IV 13 I] l x I l 11 6d \6g 9 9 18 2d- 5d W United States Patent 8 Claims. (c1. 180-4 Patent Application Ser. No. 498,314, filed Oct. 20, 1965, by Mr. Bertin, one of the inventors herein, describes a ground effect machine supported by several fluid cushions fed independently of one another and having different mechanical characteristics, for example the internal volume ofeach of these cushions. This enables the cushions to be given different characteristic frequencies of vertical oscillation, so that the assembly of the suspension of the machine tends to become aperiodic.

It is, however, desirable to simplify the design of the device providing such suspension, of example, when flexi- 'ble skirts are used to define the fluid-carrying cushions, to use standardized skirts, preferably all of the same dimenslons.

According to the invention several fluid cushions supporting a ground effect machine are given different real volumes by disposing within the cushions, whose apparent volumes may be equal, flexible and inflatable bags or chambers the volumes of which are different and which preferably play a different part, such as the support of the machine when the carrying cushions cease to be fed with pressure fluid.

In one embodiment of the invention these bags are made of inextensible material and permanently inflated at a pressure higher than that of the cushions containing them. Preferably, they are in the form of truncated cones and their reinforced bottom ends form friction and support bases.

As a modification, bags made of extensible material may be used, adjustment of the pressure in these bags enabling their volume to be modified.

In another modification, at least some of the bags are deformable and contain an independently inflated balloon. Each of the bags has an adjusted discharge valve, and their progressive collapse when the machine stops has a shock-absorbing effect intervening before the balloons act as elastic supports.

The invention will now be described with reference to the accompanying drawings in which:

FIGURE 1 shows in diagrammatic vertical section a multiple air-cushion platform according to the invention, and

FIGURES 2 and 3 are similar views of two modifications.

FIGURE 1 illustrates the principle of the invention and shows diagrammatically in vertical section a machine 1 resting on multiple air cushions 2a, 2b, 2c, six in number for example. These cushions are fed separately by means of a blower 3 with several outlets 4a, 4b, 4c in per se known manner. Each cushion 2a, b, c is defined by peripheral air-retaining means, for example identical flexible skirts 5a, b, c.

According to the invention the real internal volume provided by each of these skirts 5a, b, c for the air is made less than the apparent (external) volume of the skirts by disposition below the machine 1, Within the skirts and respectively of bags 6a, b, c of different volumes. These bags are inflated by means of a compressed gas cylinder 7 and pipes 8. Through each of them, if required, passes a flexible conduit 9 feeding the corresponding air cushion, this conduit naturally being designed to 3,332,508 Patented July 25, 1967 Withstand the excess pressure in the bag and, for example, reinforced by means of a metal spiral.

The bags are disposed at the bottom of the machine in any conventional manner for connecting a rigid to a deformable wall, for example by clamping the latter. Preferably, they are made of practically inextensible though flexible material, for example fabric coated to make it impermeable, and their inflation pressure is higher than the maximum pressure of the cushions.

Their volumes, may however, be varied during the operation of the machine, either together or differentially, by forming these bags of elastic material, different thicknesses being used for different bags.

The bags 6a, b, c naturally increase the floatability of the machine.

FIGURE 2 shows a modification of the machine in which the means for feeding the cushions 2d to 2g have not been shown. The skirts 5d and 5g can be raised by means of winches 10 or the like, and for this purpose they can have a bellows-shaped top 11. The bags 6d to 6g are each disposed on a plate 12 which is rigidly connected to the machine by cross-pieces 13 and serves to distribute uniformly the delivery of compressed air in the corresponding cushion 2d to 2g. Some of these bags, for example 6d and 6g, serve at rest as elastic supports for the machine as shown on the right of FIGURE 2. For this purpose, in addition to an appropriate length, they have a support base 18 made of rubber at the bottom. They are inflated, as before, via the pipes 8.

Such a device facilitates the pressurization of the various cushions when the machine is started, the skirts 5d, 5g shortened by means of winches 10 always being perfectly symmetrical about their axis, while the skirts 5e, 5 are only very slightly twisted because of the height of the bags 6d, 6g.

FIGURE 3 shows another embodiment in which the bags 6h not only serve to reduce the real volume of the corresponding air cushion during the movements of the machine, but also to deaden the contact of the machine with the ground during halts, the pipe 8 having an adjusted pressure relief valve 14. When stationary, the machine is supported by balloons 15 which are disposed in the bag 6h and have an independent inflation system 16, 17.

What is claimed is:

1. In a ground effect machine of the kind having a support frame designed to move along a surface and a plurality of wall means projecting from said frame toward said surface for laterally bounding a corresponding plurality of pressure fluid cushions formed against said surface, fluid pressure source means, means to supply said cushions with fluid pressure the improvement comprising inflatable flexible bags fitted entirely within said cushions and sized to occupy therein, when inflated, such volumes as to leave different effective cushion volumes for different fluid cushions, and means other than the cushion fluid pressure supplying means for supplying pressure fluid to said bags to inflate the same.

2. A ground effect machine as claimed in claim 1, wherein the bags are made of substantially inextensible, fluidtight material.

3. A ground effect machine as claimed in claim 2, wherein said material is a coated fabric.

4. A ground effect machine as claimed in claim 1, wherein said first mentioned fluid pressure supply means opens into each fluid cushion opposite said surface, and a plate spaced from said frame and extending inside each cushion, said plate being adapted to distribute evenly the pressure fluid supply to the respective fluid cushion, and means for fitting said bags to corresponding plates.

5. A ground effect machine as claimed in claim 1, further comprising an inflatable balloon in at least some of said bags, and pressure fluid supply means for inflating said balloons, separate from said means for supplying pressure fluid to said bags.

6. A ground effect machine as claimed in claim 5, further comprising a pressure relief valve in said means for supplying pressure fluid to said bags.

7. A ground effect machine as claimed in claim 1, wherein at least some of said bags comprise, at the part thereof adjacent to said surface, a surface engaging end. 8. A ground effect machine as claimed in claim 1, further comprising a flexible pressure fluid supply hose extending through said bags and opening into the respective cushions.

No references cited.

A. HARRY LEVY, Primary Examiner. 

1. IN A GROUND EFFECT MACHINE OF THE KIND HAVING A SUPPORT FRAME DESIGNED TO MOVE ALONG A SURFACE AND A PLURALITY OF WALL MEANS PROJECTING FROM SAID FRAME TOWARD SAID SURFACE FOR LATERALLY BOUNDING A CORRESPONDING PLURALITY OF PRESSURE FLUID CUSHIONS FORMED AGAINST SAID SURFACE, FLUID PRESSURE SOURCE MEANS, MEANS TO SUPPLY SAID CUSHIONS WITH FLUID PRESSURE THE IMPROVEMENT COMPRISING INFLATABLE FLEXIBLE BAGS FITTED ENTIRELY WITHIN SAID CUSHIONS AND SIZED TO OCCUPY THEREIN, WHEN INFLATED, SUCH VOLUMES 